# Revision history [back]

### endless loop using ode_solve

Im solving a system equation within a for loop, but it never ends But its ok to evaluate f1(n) outside the loop.... why?

def f1(ll):

def f1(ll):
T=ode_solver()
f = lambda t,y:[y,eqa.subs(l=ll,s=y,w=y,x=t)]
T.function=f
T.y_0=[0,1]
T.algorithm="rk4"
T.t_span=[0,1]
T.h=1
T.ode_solve(num_points=40)
s=T.solution[-1]-1
return s

for i in range(1) :g(i)


### endless loop using ode_solve

Im solving a system equation within a for loop, but it never ends But its ok to evaluate f1(n) outside the loop.... why?

def f1(ll):

 def f1(ll):
T=ode_solver()
f = lambda t,y:[y,eqa.subs(l=ll,s=y,w=y,x=t)]
T.function=f
T.y_0=[0,1]
T.algorithm="rk4"
T.t_span=[0,1]
T.h=1
T.ode_solve(num_points=40)
s=T.solution[-1]-1
return s

for i in range(1) :g(i)
range(3) :f1(i)

doesn't works except when f(1) ,otherwise  the solver is unable to end


where eq is

var('l s x')
eq=((l^2 + l)*s - 2*w*x)/(x^2 - 1)


in the other hand this works

def g(ll):
Sol=desolve_system_rk4([w,eqa(l=ll)],[s,w],ics=[0,0,1],end_points=[1.0],ivar=x,step=0.01)
return (Sol[len(Sol)-1]-1)
for i in range(3) :f1(i)


so.. whats the problem with ode_solver?

### endless loop using ode_solve

Im solving a system equation within a for loop, but it never ends But its ok to evaluate f1(n) outside the loop.... why?

def f1(ll):

    def f1(ll):
T=ode_solver()
f = lambda t,y:[y,eqa.subs(l=ll,s=y,w=y,x=t)]
T.function=f
T.y_0=[0,1]
T.algorithm="rk4"
T.t_span=[0,1]
T.h=1
T.ode_solve(num_points=40)
s=T.solution[-1]-1
return s

for i in range(3) :f1(i)

doesn't works except when f(1) ,otherwise  the solver is unable to end


where eq is

var('l s x')
x w')
eq=((l^2 + l)*s - 2*w*x)/(x^2 - 1)


in the other hand this works

def g(ll):
Sol=desolve_system_rk4([w,eqa(l=ll)],[s,w],ics=[0,0,1],end_points=[1.0],ivar=x,step=0.01)
return (Sol[len(Sol)-1]-1)
for i in range(3) :f1(i)


so.. whats the problem with ode_solver?

### endless loop using ode_solve

Im solving a system equation within a for loop, but it never ends But its ok to evaluate f1(n) outside the loop.... why?

def f1(ll):

    def f1(ll):
T=ode_solver()
f = lambda t,y:[y,eqa.subs(l=ll,s=y,w=y,x=t)]
T.function=f
T.y_0=[0,1]
T.algorithm="rk4"
T.t_span=[0,1]
T.h=1
T.ode_solve(num_points=40)
s=T.solution[-1]-1
return s

for i in range(3) :f1(i)

doesn't works except when f(1) ,otherwise  the solver is unable to end


where eq eqa is

var('l s x w')
eq=((l^2 eqa=((l^2 + l)*s - 2*w*x)/(x^2 - 1)


in the other hand this works

def g(ll):
Sol=desolve_system_rk4([w,eqa(l=ll)],[s,w],ics=[0,0,1],end_points=[1.0],ivar=x,step=0.01)
return (Sol[len(Sol)-1]-1)
for i in range(3) :f1(i)


so.. whats the problem with ode_solver?

### endless loop using ode_solve

Im solving a system equation within a for loop, but it never ends But its ok to evaluate f1(n) outside the loop.... why?

def f1(ll):

    def f1(ll):
T=ode_solver()
f = lambda t,y:[y,eqa.subs(l=ll,s=y,w=y,x=t)]
T.function=f
T.y_0=[0,1]
T.algorithm="rk4"
T.t_span=[0,1]
T.h=1
T.ode_solve(num_points=40)
s=T.solution[-1]-1
return s

for i in range(3) :f1(i)

doesn't works except when f(1) ,otherwise  the solver is unable to end
end. But f(1) or eqa(l=1) is the real solution--- :S


where eqa is

var('l s x w')
eqa=((l^2 + l)*s - 2*w*x)/(x^2 - 1)


in the other hand this works

def g(ll):
Sol=desolve_system_rk4([w,eqa(l=ll)],[s,w],ics=[0,0,1],end_points=[1.0],ivar=x,step=0.01)
return (Sol[len(Sol)-1]-1)
for i in range(3) :f1(i)


so.. whats the problem with ode_solver?